1. Technical Field
Example embodiments of the present invention relate in general to technology for machine type communication (MTC), and more specifically, to a data transmission method for MTC and an MTC apparatus, capable of increasing a data transmission capacity.
2. Related Art
Lately, Machine-to-Machine (M2M) communication that connects peripheral objects to each other through a network to enable users to easily acquire and transfer desired information at anytime and anywhere and to provide and use various services based on the acquired information is attracting a large amount of attention as a main issue for a next-generation communication market.
Conventionally, the M2M communication has been applied to sensors intended for local regions and to RFID networks; however, its use is extending to various wired/wireless networks along with diversity in purpose and characteristics of applications. Recently, interest in M2M communication based on a mobile communication network in consideration of mobility of machines, a widespread service region including islands, mountains, the field of ocean, etc., easiness of network management/maintenance/repair, security for reliable data transmission, quality of service (QoS), etc. is increasing.
The 3rd Generation Partnership Project (3GPP) which is a representative European organization for establishing standards for a mobile communication system has been performing standardization of machine type communication (MTC) since 2008, starting from studies into the validity of M2M communication in 2005.
The 3GPP has defined a “machine” as an object requiring no direct manipulation or intervention by a human, and “MTC” as a data communication type in which one or more “machines” are included. That is, the MTC can be defined as a data communication type associated with one or more entities requiring no human's intervention.
The MTC differs from the current human-based optimized mobile network service in terms of a different market scenario, data communications, low costs and effort, a very large number of potential communication terminals included, little traffic generated per terminal, etc.
The MTC can be applied to various application fields. For example, the MTC can be applied to applications for security, tracking & tracing, payment, eHealth, remote maintenance & control, smart metering, consumer devices, and the like.
Meanwhile, in the MTC-related standardization which is presently performed by the 3GPP, a technology for low-price MTC terminals is attracting strong attention.
Defined requirements for the low-price MTC terminals based on Long Term Evolution (LTE) include a data transfer rate equal to or higher than 118.4 kbps (downlink) and 59.2 kbps (uplink), significantly improved frequency efficiency compared to Global System for Mobile Communication (GSM)/Enhanced General Packet Radio Service (EGPRS) terminals, a service coverage equal to or wider than that provided by a GSM/EGPRS MTC terminal, enabling legacy LTE terminals and LTE MTC terminals to be usable at the same frequency, reuse of a conventional LTE/System Architectual Evolution (SAE) network, optimization in a Time Division Duplex (TDD) as well as in a Frequency Division Duplex (FDD) mode, supporting limited mobility and low-power consumption modules, etc.
The 3GPP discusses, as physical layer specifications for satisfying the above requirements for the low-price MTC terminals, technologies for narrow-band supporting, a single RF chain, half duplex FDD, a long Discontinued Reception (DRX) period, modulation, Hybrid-Automatic Repeat request (H-ARQ), rate matching, handover, a new category type, etc.
Particularly, the 3GPP considers a bandwidth from 1.4 MHz to 5 MHz for technology related to use of a narrow-band frequency for implementing low-price MTC terminals. However, setting of such a narrow frequency band depends on fields to which MTC is applied.
Meanwhile, in the case in which MTC terminals use a fixed narrow frequency band, there are difficulties in obtaining frequency diversity gain, which leads to deterioration of transmission efficiency of MTC terminals.
Accordingly, a new data transmission method capable of solving the problem of MTC terminals using a narrow band is needed.